Crohn's Disease

What is Crohn's Disease?

Crohn's disease is an inflammatory condition that occurs in the large intestine without any identifiable infectious cause. It is a type of chronic inflammatory bowel disease characterized by recurrent attacks that negatively affect quality of life.

What causes Crohn's Disease?

It is a disease influenced by multiple factors. Although its exact cause is not yet fully understood, it occurs in genetically predisposed individuals due to an exaggerated immune system response triggered by environmental factors.

Which parts does Crohn's Disease affect?

Crohn's disease can affect any part or multiple parts of the digestive system, from the mouth to the anus. It most commonly (in about 40% of cases) affects the area where the small intestine meets the large intestine (the ileocecal region). It can also affect only the colon in the form of Crohn's colitis (about 25% of cases),or only the small intestine (about 30% of cases).

The esophagus, stomach, duodenum, and rectum are less commonly affected areas. Compared to ulcerative colitis, the ulcers in Crohn’s disease are deeper (transmural, affecting all layers of the bowel wall) and larger. The areas between the ulcers, which are usually linear, appear normal, unlike in ulcerative colitis. This endoscopic appearance is described as a “cobblestone pattern.”

What are the types of Crohn's Disease? Why are they important?

Crohn’s disease is classified according to the location of involvement and the clinical course of the disease. The Vienna classification is commonly used today. According to the clinical course, the types are:

Inflammatory type
Stricturing type (causing narrowing)
Fistulizing type

These classifications are very important for determining the treatment approach and predicting the course of the disease.

What are the symptoms caused by Crohn’s Disease?

Common symptoms include abdominal pain, often felt in the lower right side, diarrhea, and weight loss. Before diagnosis, patients may suffer from vague abdominal pain and intermittent diarrhea for months or even years. When the small intestine or ileocecal region is involved, abdominal pain is the dominant symptom. In cases with colon involvement, symptoms more closely resemble ulcerative colitis, with bloody and mucous diarrhea being more prominent. Perianal involvement, which causes draining fistulas around the anus, is more common in patients with colon involvement. Weight loss is generally one of the accompanying symptoms.

Which diseases can Crohn’s Disease be confused with?

In cases of sudden onset bloody and mucous diarrhea accompanied by fever, infectious colitis should be excluded first. Amoebic dysentery is often mistaken for Crohn’s disease. In organ transplant patients using immunosuppressive drugs, CMV infection-related colitis, antibiotic-associated colitis (pseudomembranous colitis),and some parasitic infections can cause symptoms similar to Crohn’s disease. Crohn’s colitis is most commonly confused with ulcerative colitis.

Ulcers in the terminal ileum, the most commonly affected part of the small intestine in Crohn’s disease, can be confused with tuberculosis, lymphoma, and ulcers caused by anti-rheumatic painkillers (all common conditions).

Ulcers caused by stomach involvement may resemble stomach cancer and peptic ulcers.

How is Crohn’s Disease diagnosed?

Early diagnosis and treatment are very important to prevent complications related to the disease. For diagnosis:

Stool tests to rule out infectious causes
Seeing deep ulcers described as a “cobblestone appearance” during colonoscopy
Detection of ulcers in the ileocecal region and/or the terminal part of the small intestine by colonoscopy (it is essential to enter and evaluate the terminal ileum, although sometimes this is not possible due to strictures)
Biopsy samples taken during colonoscopy showing findings supporting Crohn’s disease
Elevated acute phase reactants such as sedimentation rate and CRP in blood tests
High levels of calprotectin in stool
Low blood levels due to iron deficiency
Imaging of the abdomen by CT or MRI in severe cases (especially to detect abscesses and fistulas)
Evaluation by MR enterography if small bowel involvement is suspected
Endoscopy if involvement of the esophagus, stomach, or duodenum is suspected
Abdominal ultrasound performed by an experienced specialist

As understood, Crohn’s disease cannot be diagnosed by a single method. Diagnosis is made by evaluating a combination of clinical, endoscopic, histopathological, and imaging findings from the tests and examinations listed above. The first and most important step is to suspect the disease.

At what ages is Crohn’s Disease most commonly seen?

The majority of patients are young adults. The first peak, called the first peak, is usually in the second decade of life (the 20s). The second peak (which includes fewer patients) occurs in the fifth and sixth decades of life.

What is the treatment for Crohn’s Disease? Is there a definitive cure?

Currently, none of the treatments available for Crohn’s disease can completely eliminate the disease from the body. The aim of treatment is to suppress the inflammatory process causing active disease and to achieve remission.

Treatment options vary depending on the location, type, and severity of the disease and include medications, nutritional changes, stress management, and when necessary, endoscopic and surgical interventions.

In fistulizing disease, treatment aims to close fistulas; in stricturing disease, it aims to suppress inflammation to improve strictures. If strictures persist despite resolution of inflammation, treatment should be performed endoscopically depending on the stricture’s location and length, or surgically if endoscopic methods are not suitable.

A common problem is closed infections (abscesses) caused by strictures and associated fistulas.

Medications used:

Corticosteroids
Immunomodulators
Antibiotics (for infections such as abscesses)
Biological agents (Infliximab, Adalimumab, Vedolizumab, Ustekinumab)
Endoscopic and surgical treatments

How should nutrition be managed in Crohn’s Disease?

Dietary restrictions should especially be applied during the active phase of the disease. In patients experiencing severe abdominal pain due to strictures, foods that may worsen the pain should be avoided. In cases where malnutrition and significant weight loss are present, nutritional support should be provided alongside medication. Once the disease enters remission, strict dietary restrictions should generally be avoided. During the active phase, dietary modifications and nutritional support should be personalized and managed under the supervision of a physician and dietitian, based on the severity and extent of the disease.

Does stress cause Crohn’s Disease?

Stress is not a direct cause of Crohn’s disease; however, it is one of the important factors that can trigger the onset of the disease and cause flare-ups in patients who are in remission. Therefore, it is important for patients to receive appropriate psychological support and to be evaluated by a psychiatrist when necessary, as part of comprehensive disease management.

When is surgery necessary in Crohn’s Disease?

Like medications, surgical treatment in Crohn’s disease does not provide a permanent cure. However, surgery can be a good option, especially in patients with ileocecal involvement who do not respond to medical treatment. In patients who develop strictures or obstructions and do not respond to drug therapy, and if the condition cannot be managed endoscopically, surgery is required. Surgical intervention is also necessary in patients with perianal fistulas that do not respond to medication and have associated abscesses. In Crohn’s colitis, total colectomy (removal of the entire colon) is not typically a recommended treatment option.

Does Crohn’s Disease affect other organs?

As in ulcerative colitis, Crohn’s disease can be associated with conditions affecting organs outside the intestine. These are referred to as extraintestinal manifestations.

The most common associated conditions include:

Joint involvement, especially inflammation of the lower back joints (ankylosing spondylitis),but other joints may also be affected
Skin lesions (such as pyoderma gangrenosum and erythema nodosum)
Eye involvement (including dry eyes, uveitis, and episcleritis)
Bile duct narrowing, known as primary sclerosing cholangitis

Which medications should be avoided in Crohn’s Disease?

Patients with Crohn’s disease should always consult their doctor before taking any medications prescribed for other conditions. In particular, the use of antibiotics (except for certain specific ones) without medical guidance and the use of anti-rheumatic painkillers (NSAIDs) can trigger flare-ups of the disease.

How should follow-up be conducted in Crohn’s Disease?

The frequency, duration, clinical type, location, and severity of flare-ups in Crohn’s disease vary from patient to patient. Since it is a lifelong condition characterized by periods of remission and flare-ups, it requires consistent treatment and follow-up. The intervals between follow-up appointments may differ depending on the patient. If a patient in remission begins to experience symptoms suggestive of a flare-up, they should contact their doctor without waiting for the next scheduled visit. This is crucial to adjust the treatment plan before the disease becomes more severe.

Does Crohn’s Disease increase the risk of colon cancer?

As a chronic inflammatory disease, Crohn’s disease increases the risk of colon cancer over time, particularly in patients whose inflammation is not well controlled. This risk is notably higher in patients with colonic involvement (Crohn’s colitis). Therefore, for patients with Crohn’s colitis (except those with isolated proctitis),annual screening colonoscopies are recommended starting 8 to 10 years after the initial diagnosis. The goal is to detect precancerous lesions or early-stage colon cancer so that treatment can be initiated promptly.